.page-content {
  display: grid;
  grid-gap: 20px;
  grid-template:
    "sidebar main"
    / 200px 1fr;
  ;
  padding: 20px;
}

aside { grid-area: sidebar; }
main { grid-area: main; }

@media (max-width: 768px) {
  .page-content {
    grid-template:
      "sidebar"
      "main";
  }  
}

aside .aside-content {
  max-width: 100%;
  display: flex;
  flex-wrap: wrap;
  position: sticky;
  top: 15px;
}

.sidebar-nav-links a:link {
  font-weight: 500;
  text-transform: uppercase;
}